Wire-feed mechanism of screwing-machines



- APPLICATION FILED QCT. 22, i919.

Patented June 7 192L- mswss,

wires s 'rras MARK THOMAS DENNE, OF RUSHDEN, ENGLAND.

earner 1 Winn-ram) ranorranrsia or sonnwrne-lvraonmns.

' nism'of screwingmachines-such as are employed for, inter alia, attaching the soles of bootsand shoes-and in particular to that type of such mechanisms in which several pivoted feed dogs or grippers are first made to grip the wire and thereafter to feed it.

My invention consists in a device (for example a floating ring that surrounds I the usual hollow spindle) which will adjust itself so that all the feed dogs will act to an equal extent in gripping and thereafter feeding the wire. The provision of such a device is very desirable because, apart from inequalities in the wire, there are sometimes imperfections in manufacture of the several parts associated to grip the wire and the result of this is that the wire is gripped unequally, or'in some cases eccentrically since the gripper which is farthest from the axis of the spindle will receive the pressure of the wire and in so doing determine its eccentricity. This is very detrimental to proper working of the machine, having regard to the great strain on the wlre when it is being screwed into the work at a high speed, and it often causes mysterious break- 2. es.

A diagrammatic illustrationof a simple constructional form of my invention is given by way of example in the accompanying drawing, in which:

Figure 1 is a side elevation, partly in section, of the spindle of a screwing machine provided with gripper closing means in accordance with the invention,

Fig. 2 is a section onthe line A, B, of

Fig. 1 showing the gripper closing means only, and

Fig. 3 is a section on the line CD of Fig. 1, showing how the grippers cooperate in gripping the wire. 7

In said drawing a indicates a hollow spindle the lower end of which has an aperture 6 to receive the shank of a nozzle (not shown) through which spindle and nozzle the screwed wire 0 passes. Rotating with Specification of Letters Patent.

Patented June '7 1921.

Application filed October 22, 1919. Serial No. 332,550.

and adapted to be reciprocated vertically V with respect to the spindle a is a sleeve 0! which carries pivotally the feed dogs or grippers 1n the usual manner,

In accordance with the particular constructlonal form of my invention illustrated I provide a floating ring or collar f which is supported so as to move in the vertical direction with a sleeve-like yoke 6 but which has 1ts inner diameter suflicie'ntly large that it may move in any direction in a plane at rightangles to the, axis of the spindle at A convenient way to support the collar thus 1s'to form the yoke 12 with a groove 21 and the collar with a groove h and to fit blade.

springs j in said grooves the center part of the springs restlng in the groove of the yoke and the ends of the'springs projecting into the groove of the collar about as shown. The springs are of a sufficient width to support the collar securely but are fairly thin so that although they will tend to maintain the collar concentric with the yoke they will not ofier much resistance to movement of the collar in a horizontal direction but will yleld readlly to permit of the ring taking up an eccentrlc position relatively to the yoke. If desired each spring may have a central pin Zr: that enters an aperture in the feed dogs or grippers Z, mounted on pins a.

Each gripper has a lug or wing m extendmg outwardly and upwardly from it, the free end of which is formed with an inclined planem with which the lower and prefera bly rounded end of the collar f engages when the yoke, 6 moves downward relatively to the sleeve d.

When the machine is in operation, as the yoke descends the collar 7'' contacts with one or more or all of the inclined planes m and thereby swings the relative pers into contact with or toward the Wire. If, for example, only one of the grippers is 1n contact with the wire, further downward movement of the yoke will not act to cause the said grippers to feed the wire but will cause the collar to be moved'in a hori zontal direction until the inclined plane m of each of the wings m becomes engaged to an equal extent, 2'. 6., until the collar exerts an equal'pressure on all the wings and consequently all the grippers will be exerting an equal pressure against the Wire. The collar therefore automatically beds itself on gripper or gripthe wings so that all the grippers will be brought to that position relatively to the wire where they will all act to an equal ex.- tent in gripping and thereafter feedingthe wire. 7

What I claim is:

1. Wire feed mechanism for screwing machines, comprising in combination a hollow spindle through which the wire passes axially, a gripper carrier adapted to be reciprocated longitudinally of the said spindle, a plurality of grippers mounted on the said carrier, and means for closing the said grippers on the wire adapted to be reciprocated on the said spindle relatively to the said gripper carrier and to adjust itself autoinati cally in any direction in a plane at right angles to the axis of the spindle to cause each of the grlppers to exert an equal pres sure on the wire.

2. Wire feed mechanism i'orscrewingnia chines, comprising in combination a hollow spindle through which the Wire passes axi-' ally, a sleeve which is slidable longitudinally on the said spindle, a plurality of grippers,

mounted on the said sleeve, a sleeve-like yoke which surrounds the sa1d sleeveand 1s slldable thereon, a gripper closing member 1n the form of a ring which surrounds the said machines,'the combination with a hollow splndle through which the wire passes axe,

ally and a plurality of grippers carried on thesaid spindle and adapted to gripand feed the wire, of gripper closing means consisting of a floating ring surrounding the spindle and adapted to adjust itself automatically in any direction in a plane at right angles to the axis of the spindle, and movable longi-i tudinally of the spindle to forcethe grippers into engagement with the wire.

MARK THOMAS DENNE. I 

